This invention relates to a novel process for preparing anionic and cationic polymers.
Cationic polymers are widely employed in water treatment, paper making, cosmetics, mineral processing and enhanced oil recovery. The polymers are generally prepared by the polymerization of quaternary ammonium monomers such as diallyldimethyl ammonium chloride, vinyl benzyl trimethyl ammonium chloride, methacryloylethyl trimethyl ammonium chloride, methacrylamidopropyl trimethyl ammonium chloride, and the like.
Anionic polymers are widely employed as dispersants, friction reducers for aqueous fluids, flocculants, and in secondary oil recovery as viscosity modifiers. The polymers are generally prepared by the polymerization of monomers such as vinyl sulfonic acid, allyl sulfonic acid, 2-acryloylamino-2,2-dimethylethane sulfonic acid, and the like, and the corresponding salts thereof.
Cationic or anionic polymers are generally prepared using procedures such as aqueous phase polymerization as described by Schildknecht (II) in Polymer Process, Interscience, 191-194 (1956) or disperse aqueous phase polymerization as described by Vanderhoff et al. in U.S. Pat. No. 3,284,393. The compositions of the polymers prepared by the aforementioned processes cannot be easily altered during the reaction process. For example, if one desires to employ various quaternary nitrogen substituents in a cationic polymer, it becomes necessary to copolymerize various monomers.
In view of the deficiencies of the prior art, it would be highly desirable to provide a versatile and convenient process for producing anionic and cationic polymers.